From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8D8CC38A2E for ; Tue, 5 Apr 2022 10:08:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351583AbiDEKCt (ORCPT ); Tue, 5 Apr 2022 06:02:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237751AbiDEIST (ORCPT ); Tue, 5 Apr 2022 04:18:19 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 452F8B7155; Tue, 5 Apr 2022 01:07:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B06F3B81B92; Tue, 5 Apr 2022 08:07:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23E4FC385A0; Tue, 5 Apr 2022 08:07:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649146041; bh=CKzhokmJcCTH/MresvNL8KHKGtQixW+DqcBdGRweJug=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jUHoeIBOFL07imKHNRs89qG46+w6w51zvP17k+yBR48Y51wB1UX9m6HJVk/cO/DBm xzfEa0QrkhFkgxzuu20Bxpu0znCmgthSOeNxt2CNGqaUiJkfDbRSFJhwQYVcUSitBb e7tYf2v1OIb8VX2IRVvOc+etzq0WbESLJFdfHQU8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ping Fang , Daniel Henrique Barboza , Michael Ellerman , Sasha Levin Subject: [PATCH 5.17 0620/1126] powerpc/mm/numa: skip NUMA_NO_NODE onlining in parse_numa_properties() Date: Tue, 5 Apr 2022 09:22:47 +0200 Message-Id: <20220405070425.834178411@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Henrique Barboza [ Upstream commit 749ed4a20657bcea66a6e082ca3dc0d228cbec80 ] Executing node_set_online() when nid = NUMA_NO_NODE results in an undefined behavior. node_set_online() will call node_set_state(), into __node_set(), into set_bit(), and since NUMA_NO_NODE is -1 we'll end up doing a negative shift operation inside arch/powerpc/include/asm/bitops.h. This potential UB was detected running a kernel with CONFIG_UBSAN. The behavior was introduced by commit 10f78fd0dabb ("powerpc/numa: Fix a regression on memoryless node 0"), where the check for nid > 0 was removed to fix a problem that was happening with nid = 0, but the result is that now we're trying to online NUMA_NO_NODE nids as well. Checking for nid >= 0 will allow node 0 to be onlined while avoiding this UB with NUMA_NO_NODE. Fixes: 10f78fd0dabb ("powerpc/numa: Fix a regression on memoryless node 0") Reported-by: Ping Fang Signed-off-by: Daniel Henrique Barboza Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220224182312.1012527-1-danielhb413@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/mm/numa.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 9d5f710d2c20..b9b7fefbb64b 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -956,7 +956,9 @@ static int __init parse_numa_properties(void) of_node_put(cpu); } - node_set_online(nid); + /* node_set_online() is an UB if 'nid' is negative */ + if (likely(nid >= 0)) + node_set_online(nid); } get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells); -- 2.34.1